5: Field patterns Flashcards
What is the use of a gold leaf electroscope?
It is used to detect electric charge
When an uncharged Perspex rod is rubbed with an uncharged dry cloth, what do the electrons transfer to?
The cloth.
This results in a negatively charged cloth and positively charged rod.
What is the name of the path a free positively charged ‘test’ charge will follow
A ‘line of force’ or a ‘field line’
What is used to produce the patterns of fields around different charged objects?
Semolina grains sprinkled in oil with an electric field set up across the surface of the oil
Describe the field lines made by two oppositely charged points.
The field lines are concentrated at the points but follow a curved path between them
Describe the field lines made by a point object near an oppositely charged plate
The field lines are concentrated at the point object but they are at right angles to the plate where they meet. The field is strongest where the lines are most concentrated
Describe the field lines made by two oppositely charged plates
The field lines run parallel from on plate to the other, meeting the plates at right angles. The field is uniform between the two plates as the field lines are parallel to each other
Define electric field strength at a point in a field
The force per unit charge on a positive test charge placed at that point
What is the unit of gravitational field strength?
Newton per coulomb (NC^-1)
Or
Volt per meter (Vm^-1)
In which direction do field lines go?
From positive to negative
